Melt butter in large skillet over medium-high heat.
Season chicken with salt and pepper; place chicken in the skillet in a single layer.
Brown chicken on both sides, ~10 minutes.
Reduce heat to low; add wine; cover skillet; simmer 20 minutes.
Transfer chicken to a warm plate.
Raise heat to medium-high; add water and vegetables to skillet; sprinkle flour over vegetables; mix well; cook until vegetables soften, ~5 minutes.
Add sour cream; mix well; remove from heat and cover. Let rest ~5 minutes